Apparatus for duplicating with the aid of stencils



Nov. 23

D. GESTETNER APPARATUS FOR DUPLICATING WITH THE AID OF STENCILS Filed Feb. 10 1925 Patented Nov. 23, 1926. u Y UNITED STATES DAVID GESTE'INEB, LONDON,

3 1 Mtg-f1 or-rice...

ENGLAND, ASSIGNOI r 1). LONDON, ENGLAND.

easzrarm 1.1mm, oi

arrm'rus iron DUPLIOA'IING wrrnrnn an) or s'rancms.

Application filed February 10, 1925, Serial No. 8,238, and in Great Britain April 10, 182.

This invention relates to duplicating with the aid of flexible stencils and more particularly such as are produced by photographic means or are stencilized by pressure.

5 Usually such stencils consist of a porous support constituted by a sheet of yoshmo paper and a coating of a gelatinizin organic colloid through apertures in whic ink is delivered on to the impression-receiving surface.

Proposals have been made to mount a plurality of stencils in such manner that each of them is caused to travel over'a plurality of inking drums but, inall these cases the machines have been so constructed as to be adapted for use with highly fluid solutions of suitable colouring matters, the cylinders being clothed with absorbent material or the stencil being mounted on a band of felt or the like.

According to the present invention a duplicating machine of the kind in question is characterized in this that for each stencil there is provided a flexible stencil carrier including flexible metallic bands between which, and associated with means whereby the stencil may be connected thereto, a sheet of gauze is secured and that the flexible I stencil carriers are each mounted upon a plurality of non-absorbent inking drums associated with means whereby an oily or greasy ink may be distributed over the peripheral surfaces of said drums.

Generally, the stencil carriers and their associated inking means will resemble the like elements of known duplicating machines such, for example, as the rotary duplicating machine sold under the registered trade mark Gyclostyle, in which the stencil carrier comprises flexible metallic bands. between which, and associated with fastening means for the stencil, a sheet of textile fabric is secured. v In order that the several impressions may be produced in their appropriate relationship on the impression-receiving surface, means are conveniently provided whereby all or certain of the stencil carriers and the impression-receiving surface may be moved relatively for adjusting the register or alignment of the several impressions and for compensating for distortion of the impressionreceiving surface during the operation of producing impressions thereon.

Thus, in accordance with the invention the several stencil carriers and their associated inking means may be arranged to be moved relatively to one another in a direct1on parallel with the direction of travel of the lmpression-receiving surface, at rightangles to the saiddirection and further in such manner that the axis of rotation of the stencil carrier may be inclined at any suitable anglewlth the direction'of travel of the impression-receiving surface.

Further, if desirable or necessary means may be provided intermediate between the several stencil carriers and their associated inking means for taking up or delivering any slack arising from the deformation of the impression-receiving surface while it is being operated upon.

A machine in accordance with the invention may be arranged to operate u on individual sheets, but conveniently t e machineis arranged to operate upon a band of material so that while, for instance, the second impression is being produced upon the band of material the first impression is being simultaneously roduced upon a further portion of the band In such case preferably the pressure roller (that is to say, the roller between which and the stencil carrier and inking means the impression-receiving material is caused to pass and by which the latter is caused to contact with the stencil) is, contrary to the practice in machines adapted to operate upon individual sheets of impression-receivm material, maintained in fixed relationship with the stencilcarrier.

Further, the opposite ends of the stencil are connected together and for this purpose securing means is associated with the stencil carrier for fastening the two opposite ends of the stencil together, such means forming p abridge between the ends of the stencil and operatlng to prevent the fabric or absorbent or porous support for the stencil contacting with the impression-receiving surface.

As will be appreciated, this mode of securing the stencil necessitates the employment of stencil sheets which are substantially nonextensible under the stresses toswhich they are subjected in actual use.

The following particulars are given by way of example to illustrate a suitable construction in accordance with the invention, reference being had to the accompanying drawing. 110

,2', 2", a plurality of inking cylinders 3 On' a-bed-plate 1 between side frames 2, the axis of the inkin' cylinders with the diare arranged in pairs, one member of each pair being vertically. above the other member thereof and with each pair of inking cylinders a distributing or waver roller 4 1s asso-' ciated in a manner similar to that in which such devices are associated with the inking cylinders. in known duplicating machines em loying flexible stencil carriers. Over each pair of inking rollers a flex1ble stencil carrier .secured to flexible steel bands '5. travel. Beneath each of the lower inking cylinders a pressure roller 6 is arran ed.

Inv the construction illustrated, t e ma: chine being designed to operate upon indlvidual sheets of paper fed from a pile 7 supported on the table 8 by the feed mechanism 9 of known construction, these pressure rollers are mountedso that during the normal 0 ration of the machine they will be perio ically retracted from the associated inking cylinder.

The periods during which the pressure roller is so retracted will synchronize with the period during which the adjacent ends of the stencil and the fastening means are passing below the lower inking cylinder with which it is associated, the moment at which the period terminates being adapted to be varied as is usual to'vary the distance between the forward edge of the sheet and the point at which the stencil commences to operate thereon. I

The means for securing this variation may be of known character and is merely indicated by the reference 10 in the accom panyin drawing, 11 being the indicator adapte to facilitate adjustment of this portion of the device through the intermediary of the adjusting screws 12.

The several pairs of inking cylinders are arranged to be driven at a fixed speed relat-ionship one with the other and normally at the same speed through the intermediary of sprockets 13 and chains 14, the several sets of rollers being set in motion by the operation of the crank-handle 15. The sheets which have been operated upon by the several stencils are finally collected in the tray 16.

With each or certain of the pairs of ink-- ing cylinders means may be associated for moving them in a direction parallel with the direction of the travel of the band of impression-receiving material which is passed between the successive stencil carriers and their associated pressure rollers. Also means are preferably associated with the several pairs of inking cylinders whereby all or certain of them may be moved in a direction at right angles to the direction of travel and also means whereby the axis of the rollers may be inclined within certain limits in order that the inclination of rection of the trave of the impression-rece ving material may be varied within certam limits.

The machine described above is designedfor operating upon individual sheets of paper. If intended for use in printing upon a band of im ression-receiving material the mechanism or feeding individual sheets from a pile thereof may be omitted or be arranged to' beput out of operation, and in such case the machine may comprise a mounting in which a roll of the im ressionreceiving material may be enga e When the machine is designed to operate upon a band of material it may be desirable mg impression is formed, and so on. In

this way, by suitablyregulating the character of the inks employed an impression of,

rich quality will be' secured, quite similar to that which is secured in known printing processes where an lmpression in the same colour is produced upon the impression-re ceiving surface by a plurality of printing operations.

A machine in accordance with the invention may-conveniently comprise six stencil carriers but the actual number of stencil carriers provided with the machine will naturally be varied to suit the requirements of particular cases.

It is to be understood that the above detailed particulars are furnished for the purpose of describing the nature of the invention and a convenient manner of carrying the same into effect, and that many variations and changes may be made in the constructional and other details without exceeding the scope of the present invention.

Havin now described my invention, what I c aim-as new and desire to secure by Letters Patent is A machine for duplicating documents, drawings and the like with the aid of flexible stencils, comprising a plurality of nonabsorbent inking drums arranged 1n groups, means associated with each group for distributing an oily ink over the peripheral surface of the individual drums thereof, a flexible stencil carrier mounted about each group of drums, means on each of said stencil carriers whereby a stencil may be secured thereto, means adapted to operate all of said groups of drums and stencil carriers in unison, feed mechanism adapted to deliver sheet material into position to be operated on by the stencil associated with the first group of inking drums, and means adapted to secure said groups of drums in such relative positions .that each of the preceding groups of drums and its associated stencil carrier will deliver to the next succeeding group the sheet material delivered by the feed mechanism to the first group.

In testimony whereof I have signed my name to this specification.

' DAVID GESTETNER. 

